Dieselten

98-octane mogas is a more dense fuel than 95-octane, that is to say it contains slightly more megaJoules per kilogram...remembering that a kilogram is a fixed weight (we are assuming a gravitational attraction of 1G throughout, and weight is mass multiplied by gravitational force) whereas a litre is a varying weight dependent on the temperature of the fuel (which affects its density). Technically we should buy our fuel by weight, not volume. We should also calculate fuel-flow in kilos per hour (or pounds per hour) instead of volumetric units per hour. That said, theoretically the denser fuel should yield slightly lower fuel-flow for horsepower developed. However, the difference in practice may be marginal, and users would have to do a cost-benefit analysis of the two fuels to determine which produced the best fuel-flow versus cost. Given the diurnal variations in fuel-pricing, such a test would need to be conducted on a daily basis in order to determine on any given day which of the two fuels gave the better value-for-money. 98 octane mogas should not contain alcohol, but will likely contain alkyl phosphate compounds as octane-enhancers. 100 octane almost certainly will contain alcohol (because alcohol raises the octane-rating slightly), and anything below 95 octane will most likely also contain alcohol. The simple test (known as a "phase-change" test, where water is used to extract alcohol from fuel, thereby increasing the apparent water-level in the sample) is also the best field-test for alcohol-adulterated fuels. Two other octane-boosting compounds may be encountered at times, namely MTBE and ETBE (methyl tertiary butyl ether and ethyl tertiary butyl ether). These compounds are not known to have adverse effects on fuel-system components, but alcohol (ethanol or methanol) are known to affect some seals and tank-linings. There is no easy test for distinguishing MTBE and ETBE from methanol or ethanol. Since MTBE and ETBE are usually more expensive than alcohol, "no expense is spared to keep the cost down." FWIW, I am running an 80HP 912 on 98-octane from a supplier just across the road from my local airport and encountering no signs of filter-clogging or waxy substances accumulating in main-jets, idle-jets etc. You pays your money and you takes your choice. 95 or 98 - both work, it's your call. One handy tip, if I may: If you are not going to fly for a while, drain your fuel tank and use the mogas in your car! The octane-enhancing compounds boil-off rapidly. Old fuel is well below nominal octane-rating and may cause detonation and engine-damage in a very short time - if you can even start the engine on it in the first place. "There is no fuel like an old fuel, and old fuel is like no fuel".

Been using Aeroshell Sport Plus 4 for about the last 100 hours, seems to run out approx $13.50/litre (GST inc). I get it on carnet from the local fuel-farm, complete with release note (which go into the aircraft maintenance file). No complaints, it is a certified aviation-grade oil recommended for the 912 series engines. No gearbox problems either. Not going back to VSX. A little on the "runny" side, but we've found nothing in the filters when we cut them open so it seems to be doing its job well. Nothing worth mentioning on the magnetic plug either.

If you passed the exam I wouldn't stress about it. As with all things, the exams will require a little "tweaking", especially this one as it is relatively new. I am assuming this was the new RA-Aus Human Factors exam you did. If you think doing exams is hard, try setting them! No matter how unambiguous you make the answers, there is always someone who can mis-interpret a question, or read it wrongly, or find the wrong answer for the right reason. With new exams it is quite possible for a less-than-perfectly-correct answer to be selected as the best out of the choices. With a bit of feedback from candidates, usually these answers get weeded out or changed to eliminate the ambiguities etc. IIWY, I'd inform the instructor who administered the exam and have him follow up with RA-Aus. I'm sure he'd appreciate the feedback. If the wheel doesn't squeak, the brakeman won't give it any oil!

Made my own bracket when my old 582 (pre-mix) was rebuilt and became oil-injected. Mounted on the sloping tubes of the upper-engine-mount. Has now done over 500 hours without cracking, bits falling off or anything else untoward. Getting the tank and bracket off the vibrating engine seems to be the main thing. The current mounting system, on the cylinder-head, is designed to fail. The chap who designed the bracket, and the mounting system, probably won an industrial design award. Usually the case for boneheadedly stupid design. There's usually an intelligence test to be an industrial designer - you have to fail. The best solution is to buy a 912-engined trike. Failing that, design and fabricate your own bracket to mount the tank on the sloping tubes of the top engine mount, with due regard to the sloping throttle-cable "mixer assembly".

582 blue-top run regularly (about 100hrs per year or better) should run for at least 700-800 hours before the alternator fails. That's time to put a new engine on. Just use a good 2-stroke oil and make sure your engine is well warmed-up before you give it full welly for takeoff. Another indicator is a Cyclone bearing test reading of 0.05mm or greater...time for new engine. Factory minimum is 0.03mm, max is 0.08mm. At 0.05mm failure can occur in relatively short time. Usually the alternator goes before the pistons/crankshaft. The 582 is a very good engine for the money.

These are automotive after-market bits, right? For car engines? Racing-car engines? Engines which produce massively varying levels of output power via gearboxes? Engines which are never operated in anything like the same manner as an aircraft engine? Engines which are never asked to warm up, then operate just below redline for five minutes, then spend a couple of hours at constant 75-80% power (and speed), then coast back home at idle, right? In other words, you are trying to convince me that parts for an engine designed to operate in one way are going to cut it in an engine run in a totally different manner, with completely different thermodynamics, stresses and horsepower-ratings? Go ahead - make my day! But the only way to rebuild a Jabiru engine is to use Jabiru engine parts and only Jabiru engine parts. If you don't, it's no longer a Jabiru engine. It may be a CP-Carrillo-Ferrere engine, but it isn't a Jabiru engine, but it most certainly isn't what the aircraft designer envisaged bolted to the front of his airframe, it isn't what the engine-designer envisaged assembled as the powerplant, and it isn't anything other than a pudding of parts which may - or may not - prove compatible. By all means experiment - and be an unpaid test-pilot. The strange thing is that in experimental aircraft, it's amazing how many builders choose to put in a reliable, proven Lycoming or Continental engine into their experimental airframe. I guess they want at least one part to be a known quantity. As Lenin so truly said, "everything is connected to everythign else", and nowhere is this more true than in the field of aircraft reciprocating piston-engines.

A couple of days ago I had the occasion to fly a J160 from Wollongong to Nowra (YSNW) and return. On takeoff at YWOL the OAT was 34 degrees, and at 2500 feet it was 36. Oil temperatures went to the 100 degree mark and stabilised there. According to the Garmin 296 when we plugged all the data in, the DA was 4661 feet, and YWOL is only 32ft amsl! We cruised to YSNW at 2500 feet to take advantage of nearly 30kts of hot tailwind. Having done a weather-flight earlier in the day I knew it got hotter the higher you went, so we we elected to maintain 2500ft for the trip. Departure from YSNW saw the OAT (measured by a probe in the wing-root fairing, shaded but in slowly circulating air) at 38 degrees...right on the max temp as advised in the a/c operating manual. With a crew of 2 and approx 70l fuel we used first-stage flaps (20deg) and got a pretty normal takeoff run and cruise-climbed at 80KIAS until we reached 1500ft in an OAT of 36 deg. During the cruise-climb the oil temp went to the top of the green arc and stabilised there. There was no cool air, and apparently freezing-level for the day was somewhere near 12,000 feet! The sea-breeze was hot, and not wishing to battle a 30kt headwind we stayed at 1500ft all the way back where we battled a 23kt headwind instead. Oil temps were monitored carefully throughout and never went into the red, but they were at the top of the green until we commenced speed reduction in the YWOL circuit before extending flaps. OAT on the ground at YWOL was a relatively comfortable 34, and during taxi after clearing the runway we observed the oil temps well back into the green. I had no concerns about structural issues, but I watched those oil temps like a hawk all the way back. We managed a cruise TAS of just on 100kts (by Garmin 296), but I really wouldn't like to fly the J160 above 38 degrees OAT due to the real potential for oil temps to get out of the comfort-zone. Toasting your oil (and engine) has little to recommend it. I'm thinking of dropping the oil out ASAP in case it's been "aged" pematurely. Oil is cheap.

Zoche (the "vapourware" engine), Thielert (company in receivership, ridiculous low TBO times for critical components), SMA (ever seen an aircraft powered by one of those?), Wilksch (huge openings in the cowling to get the air through the intercooler so performance compromised) and DAIR...and so the list goes on...aero-diesel engines. They're like honest politicians. In theory they exist, but no-one 's actually seen or heard one. However, I applaud your courage in having a go. I suspect you may well make a small fortune out of your endeavours - but you'll have to start with a large one to do it! When you have a hundred aircraft being hauled around by your engines then perhaps you will have staked a place in the aviation engine market. But remember, you are up against Textron-Lycoming, Teledyne-Continental and Rolls Royce, as well as Franklin, Rotax and Jabiru. Some of these names are very big players who will look less than favourably on an upstart newcomer. I think the suggestion to look at initially penetrating the stationary engine market is a good one...it created the PT6 from the ST6, after all. That will get you the hundreds of thousand of hours in service you'll need to really dial in the engines for aviation use. After that...if we can still get liquid hydrocarbon fuel of any sort of calorific value at an affordable price...perhaps you will have a market, even if it is only a niche market. Past experience suggests I should not hold my breath waiting to see this latest offering any time soon. I just wish I could be more optimistic about this...but I can't.

Major problems trying to get cooling air to flow over the cylinder-head in the region of the exhaust valve...and the result is usually burnt exhaust valves and seats. The only 4-stroke engine that will work on a trike is the Rotax 912 family because they use liquid cooling for the cylinder-head, and air (oil & fuel) cooling for the remainder. Forget the HKS 700E...it's a 503 replacement, not a 582 replacement. Not enough grunt, and you still have the air-cooled cylinder-head problem. No-one has invested the dollars to try and make a Subaru EA81 aero conversion work on a trike. Probably a weight problem leading to very limited fuel-capacity. They may work on gyros and the occasional RV, but not on a trike. The engine on a trike is in the absolute worst possible place for cooling airflow. At the back, in thoroughly disturbed and relatively stagnant air with little mass-flow to speak of. The propeller is likewise working in the worst air it can work in...and yet trikes fly magnificently. Go figure. Jabiru will fuel-inject their engines and give every member of RA-Aus a free, complimentary J160C long before they ever look at liquid-cooling! The Jabiru engine is designed as an air/oil/fuel-cooled aero engine from the ground up. Trying to turn it into a liquid-cooled engine would be like putting lipstick on a pig...it might look great, but it'd still be a pig!

It's hard to beat genuine single-point-grounding! Solves a lot of problems.

Went to the Jabiru website...no sign of an SB about this. The Jabiru website is my oracle for SBs etc re the Jabiru. What models of Jabiru are involved? What was the original problem that gave rise to this? Where is this documented (citation please) Who is the publishing authority? Full text of AN (if possible) would be appreciated. Did this arise from Australian Jabiru operations or what? I assume this applies to both kit-built and factory-built Jabirus. If this is the case, I find it extraordinary that a certificated aircraft could have such a design mis-feature as rudder-pedal interference when adjusted fully out ever get through certification. Still...there was that early DC-10 cargo-door problem, so certification doesn't always find everything. Basically, more information please.

I fill tanks to full, then work on 15L/hr (J160C) general average consumption, add up the hours in the Record Of Time In Service, convert to fuel burnt, and deduct amount burned from full amount to get my approximate fuel remaining. When that figure gets below 45L I refuel - all the way to the top, and start again. Tried a dipstick, found it pretty much useless. Tanks too skinny and must be absolutely level to be meaningful. Working on fuel-burn times hours flown is a better indicator IMHO.

Get the 296, you won't regret it. Mine is a little treasure, sort of ERSA in a plastic container.

G'day Ross, They were great days at Wilton then, the place is still going but not the same atmosphere now. I have a microlight and a J160C at YWOL, if ever you're down that way drop in and we'll have lunch at "The Aviator" Restaurant - meals the size of Texas for not a lot of bucks!

G'day Ross, I remember you from Wilton in the early 70s when you were working for Alan Jay, building the "Parasport" gear. Seem to recall you were doing a lot of his rigging, is that correct? (It was a while ago). Glad to hear you are still active in aviation. Like you I retired from skydiving, once in 1976, made a comeback in 87 and finally hung up the rig for good in 98, turning to microlights for affordable, fun flying. Have read a couple of articles you wrote about flights of some distance in "Pacific Flyer" (I think) a few years ago. Good articles, too. I jumped a lot with Handles, Robbo and Pete Brammall from Canberra. Handles is still around, but Robbo and Pete Brammall are no longer with us. If you're ever in YWOL we might catch up.

Pink Floyd fans amongst us will be saddened to learn of the death of keyboard player Rick Wright, a founding member of the band, from cancer, at the age of 65. I could wax lyrical abut how "The Floyd" burst onto the pop scene in the 70s, but we all know how good they were and how timeless their music is, so I won't take up the bandwidth, but just say it is a sad day for all pop music fans who appreciated the huge impact Pink Floyd had on pop music in the 70s and 80s. RIP, Rick.

Xylene. It is a carcinogen (right up there with Benzene) but it will do the job.

Being necessarily of a pessimistic nature, I am assuming the security fiasco will get far worse before it ever gets better - if it does at all. The terrorists are definitely winning and will continue to do so until some sanity prevails. With knee-jerk politicians and bureaucrats hell-bent on preserving their jobs, expanding their empires and having increasing amounts of control over the population at large, sanity will not prevail for the forseeable future. As for current affairs television, forget the commercial networks. All they are interested in is ratings. For an accurate, clinical dissection of an issue "Four Corners" is the Exocet missile of investigative journalism. It rarely misses and usually goes straight to the heart of an issue like a surgeon excising a malignant growth.

Got 100 of the plug end-nuts using the NGK part No. GSA quoted above, also a box of D9EA from my local Auto One store, took a couple of days only. 100 end-nuts cost me $15, the plugs were pretty reasonable too. D9EA are not supplied with end-nuts as they are basically a motorcycle plug and most bikes use a lead-cap that requires the threaded shaft. You buy the plugs, you buy the end-nuts, you put one on t'other. A Jab driver I know uses a smear of high-temp Loctite on the thread when he installs the end-nuts. Has had no problems with plugs as far as I am aware.

Only 14 Grand's worth of damage to the runway? They weren't trying...or is it that they're just not building aircraft as tough as they used to. Actually, as accidents go this is a cheap accident. When they spud-in a B2 Spirit bomber (and theyhave), the US taxpayer loses 2 billion US Dollars...yes, 2 billion...basically because Northrop blew out the building cost of the B2 so much the US government cut back on the number of aircraft to the point where each unit was a shade of 2 billion. ("Stealth" as Nortohrop builds it comes at a huge price) Talk about gold-plated weapons systems, the cost of developing new fighter and bomber aircraft is outstripping the ability of the USA to actually afford to buy them. Makes our 1 billion Aust Super Seasprite fiasco look like chickenfeed. Perhaps the Super Hornet program will be a bigger fiasco, topped only by the F35 fiasco when it finally arrives. Mind you, the Defence Material Organisation could turn a program to buy ten sets of bows and arrows for the ADF into a multi-million dollar fiasco. It's what they do!

Between 15-18psi will do just fine. Use a bicycle pump and a pressure gauge you can buy from Repco. Keep both in your side-pocket on the trike. Make sure you have a spare connector-piece (from pump to tube-fitting) for the pump as well because they don't last forever. You can buy some very fancy bike pumps these days, but take a tip and buy a cheap Zefal brand, just a bog-standard pump but good quality.

Five posts and still no definitive answer, but thanks to all who replied. J430:- Not harsh. I can think of several words that accurately describe your post but harsh is not amongst them. I will consider it withdrawn, irrespective of whether you do so or not. The rest:- all your comments noted, and Macnoz and Pduthoit's posts genuinely helpful, for which my sincere thanks. Next time I'll post my question on PPRUNE. Or maybe I'll just ring/email Jamie Cook.

There's a Service Bulletin on the Jabiru website regarding replacing the aileron bellcrank cover on the J160/170 family with a new one (it's the fibreglass cover over the aileron-cable bellcrank in between the seat-backs on these models). I'm curious...what was the problem with the existing cover that requires a new one to be fitted and warrants a Service Bulletin?

Buy the J160C, you won't regret it.

I have to advise, with deep regret, the passing of Microlight legend Paul Haines, who lost his battle with a brain tumour on Friday 28th March 2008. He died peacefully at his home in Stanwell Park. His funeral was held on Monday 7th April and was attended by more than 90 people, many of whom are well-known in the Australian Microlight community. Afterwards a celebration of his life was held at The Beach Kiosk, Stanwell Park, one of Paul's favourite spots. The Sydney Microlight Centre remains "Ops Normal" at this time.